The present invention relates to a braking device particularly usable for skates including a shoe composed of a quarter articulated to a shell which is in turn associated with a frame for supporting two or more wheels.
Conventional roller skates, whether constituted by a shoe associated with a support for two pairs of mutually parallel wheels or by a shoe associated with a supporting frame for two or more aligned wheels, have the problem of braking the wheels in order to adjust the speed of the skate.
It is known to use adapted pads or blocks, usually made of rubber, which are arranged at the toe or heel region of the shoe; when the user tilts the shoe or boot forwards or backwards, the free end of the pads or blocks interacts with the ground and braking is thus achieved.
However, these solutions are not optimum, since they require the user to rotate the shoe, and therefore the frame associated therewith, at the toe or at the heel, and this can cause losses of balance with consequent falls.
U.S. Pat. No. 1,402,010 is also known which discloses a roller skate provided with a band which can be secured on the leg of the user above the malleolar region and to which a rod is connected.
The rod surrounds the leg to the rear and is then curved so as to laterally affect it until it is associated, at its ends, in the malleolar region, with a lever system which is articulated to a structure protruding from the wheel supporting frame.
The lever system protrudes to the rear of the frame and is connected to a plate which is shaped approximately complementarily to the curvature of part of an underlying facing wheel.
This solution is not free from drawbacks: first of all, a relative movement is produced between the band and the leg during skating, and this does not make its use comfortable due to the continuous rubbing of the band on the leg.
Furthermore, the plate is activated every time the user bends his leg backwards beyond a given angle, with no actual and easy possibility of varying this condition.
Furthermore, each user has a different leg shape, thus producing a braking action at different rotation angles because the rod length is the same.
Furthermore, the rod rests and presses on the malleolar region, and this can cause discomfort or can cause accidental impacts; finally, considerable wear of the wheel is observed.
U.S. Pat. No. 4,275,895 is known as a partial solution to this drawback; this patent discloses a brake for skates provided with two pairs of mutually parallel wheels, which acts at the rear wheels.
The brake is constituted by a flap which is associated with the shoe in a rearward region and with which a plate is associated in a rearward position; the plate is pivoted at the supporting frame of the shoe.
The plate has, at its free end, a transverse element on which a pair of C-shaped elements is formed at the lateral ends; following a backward rotation imparted to the flap, said C-shaped elements interact with the rear wheels facing them, in that they interact with the rolling surface of said wheels.
However, even this solution has drawbacks: it is in fact structurally complicated and thus difficult to industrialize: furthermore, it entails the presence of adapted springs suitable to allow the flap to resume the position in which the pair of C-shaped elements does not interact with the wheels, thus further increasing structural complexity.
Furthermore, the structural configuration of the brake causes the pair of C-shaped elements to interact with the wheel even upon a minimal backward rotation imparted to the flap and thus even for involuntary movements, and this creates unwanted braking actions and thus possible losses of balance or lack of coordination.
Finally, the interaction of the C-shaped element at the rolling surface of the wheels leads to rapid wear of the wheels and thus to non-optimum rolling, which necessarily entails continuous replacement of the wheels.
U.S. Pat. No. 4,300,781 discloses a braking device for skates which comprise pairs of mutually parallel wheels.
The brake is constituted by a plate transversely pivoted at the rear end of the frame for supporting a shoe; blocks are associated with the ends of the plate and face the rolling surface of the pair of rear wheels.
The brake is activated by using a cable suitable to rotate the plate in contrast with a spring associated with the support for the pair of front wheels, so as to move the blocks into contact with the rolling surface of the pair of rear wheels.
The cable can be activated by means of rings or handles associated with a band which can be arranged on the legs of the user by virtue of the presence of temporary connection means.
However, this solution has considerable drawbacks: first of all, activation of the brake can lead to possible losses of balance during sports practice, because the user does not assume, with his body, a position suitable to control the sudden speed reduction; brake activation in fact involves only the skater's hand.
Furthermore, since the sport can be practiced while wearing trousers, when the rings are pulled the band may slip along the trousers or make them slide along the leg, hindering the braking action.
Furthermore, there is a loose cable which in addition to being a hindrance to the skater can accidentally catch during skating, especially since coordination of the arm-leg movement rhythmically moves the legs laterally outwards.